| 1. |
- Asplund, M, et al.
(författare)
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Toxicity evaluation of PEDOT/biomolecular composites intended for neural communication electrodes
- 2009
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Ingår i: BIOMEDICAL MATERIALS. - : IOP Publishing. - 1748-6041 .- 1748-605X. ; 4:4, s. 045009-
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Tidskriftsartikel (refereegranskat)abstract
- Electrodes coated with the conducting polymer poly(3,4-ethylene dioxythiophene) (PEDOT) possess attractive electrochemical properties for stimulation or recording in the nervous system. Biomolecules, added as counter ions in electropolymerization, could further improve the biomaterial properties, eliminating the need for surfactant counter ions in the process. Such PEDOT/biomolecular composites, using heparin or hyaluronic acid, have previously been investigated electrochemically. In the present study, their biocompatibility is evaluated. An agarose overlay assay using L929 fibroblasts, and elution and direct contact tests on human neuroblastoma SH-SY5Y cells are applied to investigate cytotoxicity in vitro. PEDOT: heparin was further evaluated in vivo through polymer-coated implants in rodent cortex. No cytotoxic response was seen to any of the PEDOT materials tested. The examination of cortical tissue exposed to polymer-coated implants showed extensive glial scarring irrespective of implant material (Pt:polymer or Pt). However, quantification of immunological response, through distance measurements from implant site to closest neuron and counting of ED1+ cell density around implant, was comparable to those of platinum controls. These results indicate that PEDOT: heparin surfaces were non-cytotoxic and show no marked difference in immunological response in cortical tissue compared to pure platinum controls.
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| 2. |
- Oliynyk, Igor, et al.
(författare)
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Azithromycin increases chloride efflux from cystic fibrosis airway epithelial cells
- 2009
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Ingår i: Experimental Lung Research. - : Taylor & Francis. - 0190-2148 .- 1521-0499. ; 35:3, s. 210-221
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Tidskriftsartikel (refereegranskat)abstract
- It was investigated whether azithromycin (AZM) stimulates chloride (Cl−) efflux from cystic fibrosis (CF) and non-CF airway epithelial cells, possibly secondary to up-regulation of the multidrug resistance protein (MDR). CF and non-CF human airway epithelial cell lines (CFBE and 16HBE) were treated with 0.4, 4, and 40 μ g/mL AZM for 4 days. Cl− efflux was explored in the presence or absence of specific inhibitors of CFTR and alternative Cl− channels. Six CF patients received AZM (500 mg daily) for 6 months. The percentage of predicted forced vital capacity (FVC%), forced expiratory volume (FEV1%), and the number of acute exacerbations were compared before and after treatment. Nasal biopsies were taken before and after treatment, and mRNA expression of MDR and CFTR was determined by in situ hybridization. A significant dose-dependent increase of Cl− efflux from CFBE cells (but not from 16HBE cells) was observed after AZM treatment. A CFTR inhibitor significantly reduced AZM-stimulated Cl− efflux from CFBE cells. A significant improvement in FEV1%, and fewer exacerbations were observed. AZM treatment did not affect mRNA expression of MDR and CFTR. The stimulation of Cl− efflux could be part of the explanation for the clinical improvement seen among the patients.
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| 3. |
- Thaning, Elin M., et al.
(författare)
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Stability of Poly(3,4-ethylene dioxythiophene) Materials Intended for Implants
- 2010
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Ingår i: Journal of Biomedical Materials Research - Part B Applied Biomaterials. - : Wiley. - 1552-4973 .- 1552-4981. ; 93B:2, s. 407-415
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Tidskriftsartikel (refereegranskat)abstract
- This study presents experiments designed to study the stability of the conducting polymer poly(3,4-ethylene dioxythiophene) (PEDOT), under simulated physiological conditions using phosphate-buffered saline (PBS) and hydrogen peroxide (H2O2) (0 01M) at 37 degrees C over a 5- to 6-week period Voltage pulsing in PBS was used as an additional test environment The influence of switching the counter ion used in electropolymerization from polystyrene sulphonate (PSS) to heparin was investigated Absorbance spectroscopy and cyclic voltammetry were used to evaluate the material properties Most of the samples in H2O2 lost both electroactivity and optical absorbance within the study period, but PEDOT.PSS was found slightly more stable than PEDOT heparin. Polymers were relatively stable in PBS throughout the study period, with around 80% of electroactivity remaining after 5 weeks, disregarding delamination, which was a significant problem especially for polymer on indium tin oxide substrates Voltage pulsing in PBS did not increase degradation. The counter ion influenced the time course of degradation in Oxidizing agents.
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| 4. |
- Wibeck, Victoria, 1974-, et al.
(författare)
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Stories of Transformation : A Cross-Country Focus Group Study on Sustainable Development and Societal Change
- 2019
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Ingår i: Sustainability. - : MDPI. - 2071-1050. ; 11:8
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Tidskriftsartikel (refereegranskat)abstract
- Societal transformation is one of the most topical concepts in sustainability research and policy-making. Used in many ways, it indicates that nonlinear systematic changes are needed in order to fully address global environmental and human development challenges. This paper explores what sustainability transformations mean for lay focus group participants in Cabo Verde, China, Fiji, Sweden, and the USA. Key findings include: (a) Tightly linked to interpersonal relationships, sustainability was seen as going beyond the Sustainable Development Goals to include a sense of belonging; (b) transformations were framed as fundamental changes from today’s society, but most participants stated that transformation pathways need to splice new structures into the old; (c) new technologies are key engines of change. Yet, the most common drivers were awareness, education, and knowledge sharing; and (d) regardless of whether state-centric or decentralized governance was preferred, personal action was seen as essential. The focus groups displayed a shared understanding across the geographical settings; a common realization of profound sustainability predicaments facing societies across the world; and a desire for fundamental change towards a more sustainable way of life.
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